Controllable drive of optics of a copier

Abstract

A method of controllably driving optics of a copier in the form of a scanner which is movable relative to an original document being laid on a glass platen. The optics is usually returned in a high-speed return mode after imagewise exposure so as to enhance rapid copying. In a two-sided or a composite copy mode in which a paper sheet is driven into an image forming station of the copier before the optics reaches a timing for starting forming an image, the high speed return mode for controlling the optics is switched over to a low-speed return mode.

What is claimed is: 
     
       1. A method for controlling the driving of a scanner over a glass platen in a photocopier during an exposure and a return, comprising the steps of: providing a motor for driving said scanner;   generating movement signals in response to the movement and direction of said scanner;   selecting the speed and direction of the motor in accordance with said movement signals and manually input information including a mode input;   switching between a high speed return and a low speed return according to said manually input information;   selecting a low speed return for a particular mode, in which a first image forming operation and a subsequent second image forming operation are performed on a paper sheet, such that a low speed return is selected in said first image forming operation, and a high speed return for other modes; and   generating motor driving signals to drive said motor in accordance with the selected speed and direction.   
     
     
       2. The method according to claim 1, wherein a low speed return is selected for a 2-sided/composite mode and a high speed return is selected for other modes. 
     
     
       3. The method according to claim 1, wherein the speed of the return varies over the position along the return path. 
     
     
       4. The method according to claim 3, wherein the speed increases over a first portion of the return, remains constant over a second portion of the return and decreases over a third portion of the return. 
     
     
       5. The method according to claim 4, wherein the speed in the second portion is 1200 mm/sec for a high speed return and 600 mm/sec for a low speed return. 
     
     
       6. A method as claimed in claim 1, wherein said particular mode is a 2-sided/composite mode.